Added rbf_inv.py kernel which is parametrised with the variances

GPy/kern/constructors.py

@@ -5,6 +5,23 @@ import numpy as np
 from kern import kern
 import parts
 
+
+def rbf_inv(input_dim,variance=1., inv_lengthscale=None,ARD=False):
+    """
+    Construct an RBF kernel
+
+    :param input_dim: dimensionality of the kernel, obligatory
+    :type input_dim: int
+    :param variance: the variance of the kernel
+    :type variance: float
+    :param lengthscale: the lengthscale of the kernel
+    :type lengthscale: float
+    :param ARD: Auto Relevance Determination (one lengthscale per dimension)
+    :type ARD: Boolean
+    """
+    part = parts.rbf_inv.RBFInv(input_dim,variance,inv_lengthscale,ARD)
+    return kern(input_dim, [part])
+
 def rbf(input_dim,variance=1., lengthscale=None,ARD=False):
     """
     Construct an RBF kernel

GPy/kern/parts/__init__.py

@@ -20,3 +20,4 @@ import spline
 import symmetric
 import white
 import hierarchical
+import rbf_inv